1. Field of the Invention This invention relates to a method and apparatus for molding containers, and more particularly to a method and apparatus for molding plastic containers having a neck with closure attachment means by injection-blow molding. This invention also relates to a novel container formed by the new method and with the new apparatus for injection-blow molding.
2. Description of the Prior Art
Containers are commonly molded with an externally threaded neck for use with an internally threaded closure to cover and seal the container. With conventional injection-blow molding equipment and techniques the external threads have seams or parting lines which for certain applications may be undesireable. One aspect of the present invention provides a method and machinery for producing external neck threads without such parting lines.
In a dripless type of container/closure package, it is desirable to provide a neck finish with a pour spout to dispense the container product over the threads so they do not become gunked up and make a mess or cause a sealing problem. When the closure is to act as a measuring cup, it is also desireable to provide internal threads further reducing the possible mess and allowing the product remaining in the closure to drain back into the container when the closure is reapplied to the container neck. This has led to the development of various internally threaded inserts with and without pouring spouts which can be separately molded and affixed in some manner to the container neck. Another aspect of the present invention is the provision of a new method and apparatus for integrally molding the container neck finish with internal or external threads and a pour spout to provide a new unitary structure.
While threads are the conventional fastening means between the closure and container neck, the invention also contemplates a method and apparatus for forming other fastening or attachment means such as a snap flange on the container neck which will coact with a bead on the closure.
Regardless of the selection of internal or external threads or alternative fastening means, it is often desirable or necessary to provide a child resistant and/or a tamper indicating feature by an appendage molded on the container which coacts with the closure. The instant invention contemplates apparatus and a method for forming such child resistant and tamper indicating features by integrally molding such appendages concentrically around the neck finish which may or may not have a pour spout.